Avriel Benjamin "Avi" Kaplan won what show as part of the group Pentatonix?
The Sing-Off
-1
Section::::Abstract.
Pentatonix
33673230
-1
Section::::Abstract.
Pentatonix
33673230
-1
Section::::Abstract.
Pentatonix
33673230
-1
Section::::Abstract.
Avi Kaplan
38574561